Traffic wave

About: Traffic wave is a research topic. Over the lifetime, 2106 publications have been published within this topic receiving 62117 citations. The topic is also known as: phantom traffic jam & ghost jams.

Traffic Behavior in a Two-Lane System Consisting of a Mixture of Buses and Cars

Abstract: In this paper, a two-lane traffic system consisting of a mixture of buses and cars is studied. The buses stop at each bus stop to pick up passengers and are not allowed to change lane. The cars may change lane when hindered by preceding vehicles. Our simulations show that with a fixed number of buses, four states of the traffic system are identified. The spatial-temporal plots of the four traffic states, and the trajectories of buses at different densities are presented. A gradual transition instead of sharp phase transition from bunching state to homogeneous state of the buses is found. Next, we study the system behavior at different number of bus stops, and an optimal number of stops is suggested. Finally, the influence of bus stops on the fundamental diagram is studied.

Quantifying non-recurrent traffic congestion caused by freeway work zones using archived work zone and ITS traffic data

Abstract: Non-recurrent traffic congestion has been estimated using the capacity and the number of closed lanes in work zones and the upstream traffic demand of work zones. However, the number of closed lanes may be meaningless due to operational strategies, such as using the shoulder area and composing an additional lane by temporarily reducing the existing lane width to mitigate traffic congestion. The objective of this study is to develop a method to quantify non-recurrent traffic congestion caused by freeway work zones based on traffic flow data and spatio-temporal work zone information. In addition, to demonstrate the efficacy of the developed method, a case study is performed using 1-year historical traffic data and work zone data on major freeways in Korea.

Traffic flow forecasting

Abstract: This paper presents a review of methods used to perform dynamic traffic forecasting. New models for tracing and forecasting of congested spatial-temporal patterns on highways are examined. These include ASDA (automatic tracing of moving traffic jams) and FOTO (Forecasting of traffic objects). The advantage of these models is that they allow for the tracing and prediction of macroscopic spatial-temporal properties of traffic patterns without any validation of model parameters at different conditions. In addition, a macroscopic model for dynamic traffic forecasting in urban areas is described. The model, which allows for the prediction of macroscopic characteristics of traffic (such as queue lengths at traffic signals and link travel times), is shown to have a calculation time that can be several thousand times shorter than that of a microscopic traffic model.

Calibration of transyt platoon dispersion model for passenger cars under low-friction traffic flow conditions (abridgment)

Abstract: The calculation of delay and stops by the TRANSYT program and in turn the effectiveness of the signal timings resulting from its optimization procedure depend on the ability of its platoon dispersion model to accurately predict traffic flow patterns from one signal to another. Therefore, calibration of the dispersion factor alpha and travel-time factor beta in the model is important to the successful implementation of the TRANSYT program. However, because of limited research, a definitive description of the relationship between the appropriate values of alpha and beta and roadway conditions does not exist. The objective of this research was to contribute to the ultimate development of a definitive description of this relationship by calibrating this model for passenger cars under low-friction traffic flow conditions. Platoon dispersion studies were conducted on six arterial street segments (2 two-way two-lane segments and 4 four-lane divided segments). Traffic flow patterns of nearly 1700 platoons were analyzed. The results indicated that less platoon dispersion was observed in this study than has been found in other studies of low-friction traffic flow conditions. It was concluded that appropriate values of alpha and beta for passenger cars under these conditions are alpha equal to 0.21 and beta equal to 0.97 on two-way two-lane streets and alpha equal to 0.15 and beta equal to 0.97 on four-lane divided streets. (Author)

Development and Evaluation of an Advanced Dynamic Lane Merge Traffic Control System For 3 To 2 Lane Transition Areas in Work Zones

Abstract: The majority of safety hazards and resulting traffic crashes that occur in lane closure areas in work zone are often due to the aggressive behavior of some drivers. The late lane merge phenomenon occurs when some drivers try to avoid slow moving traffic by traveling in the lane that is about to end, and then attempt to force a merge in the through lane at the last moment. In an attempt to alleviate such aggressive driver behavior at work zones an innovative traffic control system was developed in Michigan for two (2) to one (1)-lane transition areas in work zones, which was found to be effective. In the current study, The Michigan Department of Transportation (MDOT) and Wayne State University Transportation Research Group have jointly developed a advanced dynamic early lane merge traffic control system (DELMTCS) for three (3) to two (2)-lane transition areas in work zones, creating an enforceable no passing zone to encourage motorists to make an early merge. During the year 2002, the system was designed for a right lane closure and in the year 2003 it was again set up for a left-lane closure. The effectiveness of the DELMTCS in terms of reducing delay, aggressive driver behavior and increasing average travel speed was evaluated using the field data collected at the study area before and after implementing the DELMTCS. Results of the evaluation study indicate that a smoother traffic flow is achieved by the installation of the DELMTCS. Also, the average delay per vehicle to pass through the work zone and the number of aggressive driving maneuvers decreased due to the installation of the DELMTCS in a work zone on the I-94 freeway in Michigan.